Demonstration of code-division multiplexing with synchronous orthogonal coding using fiber Bragg gratings

Fiber Bragg grating for spectral phase optical code-division multiple-access encoding and decoding

“…It can be seen from this figure that there are 15 peaks that correspond to the time delay of 15 subgratings. The value of the step time delay is given approximately by t nϪ1 ϭ (n eff z nϪ1 )/c in approximation (14), which is a simplified expression of the transmission characteristics of the encoder/decoder. It should also be noted that the intensity of the first subpulse is much higher than that of the others, as the intensity of each subpulse except the first is reduced because of the reflection spectrum overlap between adjacent subgratings.…”

“…In recent years, the rapid development of FBG fabrication technology has reached a stage at which the optical phase of the light reflected from an individual grating can be accurately controlled, which allows the optical phase to be used as a coding parameter 8,9 and thus opens the way to use FBGs to perform effective encoding/decoding functions in an OCDMA system. [10][11][12][13][14] A spectral phase encoder/decoder based on a step chirped fiber Bragg grating (SCFBG) has been experimentally demonstrated by Grunnet-Jepsen et al [12][13][14] The SCFBG originates from traditional spectral phase encoding/decoding by use of a FSGP configuration 6,7 and has the advantage of high-coupling efficiency in optical fibers. Additional theoretical analysis is still needed to improve the performance of this kind of OCDMA encoder/ decoder.…”

Composed Multicore Fiber Structure for Extended Sensor Multiplexing with Fiber Bragg Gratings

“…Code division multiplexing is another recent development in the field of fiber Bragg gratings detection. It combines both, temporal and spectral information to identify a single sensor in a sequence [ 12 , 13 , 14 ]. This technology extends the sensing length by using sophisticated instrumentation and signal processing.…”